Emoji
Available for: All Apple Watch models
Impact: Processing an emoji under certain configurations may lead to
a denial of service
Description: A denial of service issue was addressed with improved
memory handling.
CVE-2018-4290: Patrick Wardle of Digita Security

Kernel
Available for: All Apple Watch models
Impact: A local user may be able to read kernel memory
Description: An out-of-bounds read issue existed that led to the
disclosure of kernel memory. This was addressed with improved input
validation.
CVE-2018-4282: Proteas of Qihoo 360 Nirvan Team

libxpc
Available for: All Apple Watch models
Impact: An application may be able to gain elevated privileges
Description: A memory corruption issue was addressed with improved
memory handling.
CVE-2018-4280: Brandon Azad

libxpc
Available for: All Apple Watch models
Impact: A malicious application may be able to read restricted memory
Description: An out-of-bounds read was addressed with improved input
validation.
CVE-2018-4248: Brandon Azad

LinkPresentation
Available for: All Apple Watch models
Impact: Visiting a malicious website may lead to address bar spoofing
Description: A spoofing issue existed in the handling of URLs. This
issue was addressed with improved input validation.
CVE-2018-4277: xisigr of Tencent's Xuanwu Lab (tencent.com)

WebKit
Available for: All Apple Watch models
Impact: Processing maliciously crafted web content may lead to an
unexpected Safari crash
Description: A memory corruption issue was addressed with improved
memory handling.
CVE-2018-4270: found by OSS-Fuzz

WebKit
Available for: All Apple Watch models
Impact: A malicious website may be able to cause a denial of service
Description: A race condition was addressed with additional
validation.
CVE-2018-4266: found by OSS-Fuzz